Detective Drosnin stopped by Ms. Gray's house to inform her that the creep who had been stalking her years ago had just escaped from prison. She seemed to take the news fairly well, and was very polite, though she didn't invite him in.

"You know how demented he is, I'm worried that he'll come after you. Who knows what he might try!" Detective Drosnin said.

"Oh, I'm sure I have nothing to worry about," she replied. But she did sound pretty nervous.

"Would you like me to assign a security detail to you?" he asked.

"Oh, no. I'm a teacher for heaven's sake! Having bodyguards following me around would just scare the students at my school."

"Well, please give me a call or send me an email if you see anything suspicious at all. In fact, send me an email later no matter what, just to let me know that you're alright."

"I will definitely do that!" Ms. Gray replied.

Detective Drosnin got in his car and started back to the station, but after only a few minutes his phone buzzed to inform him that he had an email from Ms. Gray. It read:

This morning I tried a fun new seating style for the kids during the morning assembly. I helped arrange them into rows of twenty one. The kids didn't care, but I really loved it. I liked the second column the best.

"Why on earth would I care!?" he thought to himself. But then he remembered her passion for codes and realized she may be trying to tell him something. He took a closer look at her email, and couldn't believe what he found!

Detective Drosnin tried arranging the letters in Ms. Gray's email the way she described arranging the kids at her school, into rows of twenty one. Then he took a look at the second column like she suggested: